The Breguet 691 AB2 was a two-seat attack bomber developed from the Br 690 twin engined fighter. By the time the first Br 690 made its maiden flight on 23 March 1938 the Potez 631 had already won the fighter competition it had been designed for, but early tests of the new Breguet aircraft were very promising, and so on 14 June 1937 the Armée de l'Air ordered 100 aircraft, not as a fighter but as the Breguet 691 AB2 two-seat attack bomber. This involved making a series of changes to the aircraft, most important of which saw the navigator removed and a bomb bay put in his place. The Br 690 had been armed with two forwarding firing cannon. On the Br 691 one of these was retained, but the other was replaced with two 7.5mm machines guns. All three of these guns were angled down at 15 degrees to allow for long strafing runs. The first hundred aircraft were to be powered by two 700hp Hispano-Suiza 14AB10/11 engines, with any further aircraft using a 745hp 14AB12/13.
The prototype Br 691 flew on 22 March 1939, the first production aircraft was completed on 15 May and the first aircraft was taken on charge by the Armée de l'Air in June 1939. Only 75 were produced before production switched to the Breguet 693, a chance made because the Hispano-Suiza engine proved to be unreliable.
Groupe de Bombardement d'Assaut (GBA) I/54 was the first unit to receive the Breguet 691, starting in October 1939. By the time of the German attack in May 1940 GBA I/51 and II/51 were partly equipped with the Breguet 691 and partly with the Potez 633. GBA I/54 and II/54 operated the Breguet 691 for a short time before reequipping with the more reliable Breguet 693.
Sources differ wildly as to the number of Breguet 691s lost during the Battle of France, ranging from five to twenty five! The lower figure is the more credible, reflecting the limited number of the older aircraft in service in May 1940 and the relatively low casualties suffered by GBA I/51 and II/51. The Br 691 was not used by the Vichy Metropolitan air force to equip its two Assault Bomber Groups, both of which used a mix of Breguet 693s and Breguet 695s.